Measurement of the B⁰-B⁰ and B_s⁰-B_s⁰ production asymmetries in pp collisions at √s = 7 TeV

The B0–B0 and B0s –B0s production asymmetries, AP(B0) and AP(B0s ), are measured by means of a timedependent analysis of B0 → J/ψ K∗0, B0 → D−π+ and B0s → D−s π+ decays, using a data sample corresponding to an integrated luminosity of 1.0 fb−1, collected by LHCb in pp collisions at a centreof-mass energy of 7 TeV. The measurements are performed as a function of transverse momentum and pseudorapidity of the B0 and B0s mesons within the LHCb acceptance. The production asymmetries, integrated over pT and η in the range 4 < pT < 30 GeV/c and 2.5 < η < 4.5, are determined to be AP(B0) = (−0.35 ± 0.76 ± 0.28)% and AP(B0s ) = (1.09 ± 2.61 ± 0.66)%, where the first uncertainties are statistical and the second systematic.